Abstract

Integrated astrophotonic spectrometers are integrated variants of conventional free-space spectrometers that offer significantly reduced size, weight, and cost and immunity to alignment errors, and can be readily integrated with other astrophotonic instruments such as nulling interferometers. Current integrated dispersive astrophotonic spectrometers are one-dimensional devices such as arrayed waveguide gratings or planar echelle gratings. These devices have been limited to ${10^4}$ resolving powers and ${\lt}1000$ spectral bins due to having limited total optical delay paths and 1D detector array pixel densities. In this paper, we propose and demonstrate a high-resolution and compact astrophotonic serpentine integrated grating (SIG) spectrometer design based on a 2D dispersive serpentine optical phased array. The SIG device combines a 5.2 cm long folded delay line with grating couplers to create a large optical delay path along two dimensions in a compact integrated device footprint. Analogous to free-space crossed-dispersion high-resolution spectrometers, the SIG spectrometer maps spectral content to a 2D wavelength-beam-steered folded-raster emission pattern focused onto a 2D detector array. We demonstrate a SIG spectrometer with ${\sim\!}100\;{\rm{k}}$ resolving power and ${\sim}6750$ spectral bins, which are approximately an order of magnitude higher than previous integrated photonic designs that operate over a wide bandwidth, in a $0.4\;{\rm{mm}}^2$ footprint. We measure a Rayleigh resolution of $1.93 \pm 0.07\;{\rm{GHz}}$ and an operational bandwidth from 1540 nm to 1650 nm. Finally, we discuss refinements of the SIG spectrometer that improve its resolution, bandwidth, and throughput. These results show that SIG spectrometer technology provides a path towards miniaturized, high-resolution spectrometers for applications in astronomy and beyond.

© 2021 Optical Society of America

Full Article  |  PDF Article
More Like This
Serpentine optical phased arrays for scalable integrated photonic lidar beam steering

Nathan Dostart, Bohan Zhang, Anatol Khilo, Michael Brand, Kenaish Al Qubaisi, Deniz Onural, Daniel Feldkhun, Kelvin H. Wagner, and Miloš A. Popović
Optica 7(6) 726-733 (2020)

Compact 2D serpentine optical phased array

Yangming Ren, Lingxuan Zhang, Wei Zhao, Guoxi Wang, NingNing Feng, Wei Wu, Xiaochen Sun, and Wenfu Zhang
Appl. Opt. 60(24) 7158-7163 (2021)

Ultrafast laser inscription of asymmetric integrated waveguide 3 dB couplers for astronomical K-band interferometry at the CHARA array

Aurélien Benoît, Fraser A. Pike, Tarun K. Sharma, David G. MacLachlan, Aline N. Dinkelaker, Abani S. Nayak, Kalaga Madhav, Martin M. Roth, Lucas Labadie, Ettore Pedretti, Theo A. ten Brummelaar, Nic Scott, Vincent Coudé du Foresto, and Robert R. Thomson
J. Opt. Soc. Am. B 38(9) 2455-2464 (2021)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Data Availability

Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (5)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (9)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Metrics